Releasing clamp



July 4, 1933. l K A' HAWLEY A1,916,950

RELEASING CLAMP Filed July l1, 1929 VENTOR ATTORNEY Patented July 4, 1933 TED STATES PTENT ortica t KENT' A. HAWLEY, 0F BALTIMORE, IIIARYLAND, ASSIGNOR TO LOCKE INSULATOR CORPORATION, OF BALTIMORE, MARYLAND, A CORPORATION OF MARYLAND RELEASING CLAMP Application filed July 11,

v The invention relates to means for susn pending the conductors of current transmission lines and has special reference to suspension clamps. Ei It is well known that it is customary to support transmission line conductors by means of clamps located at the botttom of strings or chains of insulators which are in turn hung from towers located considerable distances apart. lt is a fact that snow or ice and sleet frequently collects on the conductor at one side of a point of suspension but not on the other side as for example at the edge of a storm area or when there are differences in temperature or other climatic conditions along the line. Furthermore it frequently occurs, especially in mountainous sections that one or more spans of the conductor may be subjected to the influence of high winds. In either event, and under other circumstances of a more or less analogous nature which may readily suggest themselves, it is apparent that there is an excessive strain at one side of a supporting tower and unless the tower is of excessively heavy construction, that is to say heavier than would reasonably be provided, there is a certain danger that the tower may be pulled out of plumb. Of course under such circumstances the insulator strings are also pulled out of place anc dam-age thereto may easily occur.

lt is with the abo-ve facts in view that l have devised the present invention which has for its general object the provision of a conductor clamp capable of automatically releasing or at least decreasing its grip upon the occurrence of an excessive strain atY one side or the other of the clamp and whatever support it is hung` from. An important object of the invention is to provide a releasing clamp which will under ordinary conditions exert a powerful clamping action upon the cable but which is so constructed as to permit the cable to slip 'J through until the strains have become equalized.

' Another Aobject is to provide a releasing clamp of this type which may regain its clamping ability or re-exert its clamping action upon the cessation of the abnormal strain 1929. Serial No. 377,565.

, also a feature that the distorted element may reassume its natural or normal condition so that the device may regain its clamping function without it being necessary to make any repairs or replacements.

Another important object of the invention is to provide a clamp of this type which does not depend on springs for its holding action but which has, on the contrary, positive means for applying a clamping force to the conductor.

An additional object is to provide a device of this type which will consist of but a few parts, certain of which are more or less standard among insulator manufacturing companies, and which will consequently be inexpensive to make in addition to being easy to apply or install, positive in action, eilicient and durable in service, and a general improvement in the art. y

To the attainment of the. foregoing and other objects and advantages, the invention preferably consists in the details of construction and the arrangement and combination of parts to be hereinafter more fully described and claimed, and illustrated in the accompanying drawing in which:

` Figure l is a side elevation of my clamp showing it in normal position upon'a conductor,

Figure 2 is a similar View with parts broken away and in section but showing the releasing action,

Figure 3 is a view partly in end elevation and partly in central cross section,

Figure 4 is a detail plan view of the upper clamping member alone,

Figure 5 is a side elevation thereof.

Referring more particularly to the drawing, it will be observed that I have shown a clamp for supporting a. conductor 1, the clamp embodying a main or lower clamping member 2 having a transversely curved seat 3 rfor the conductor, this seat being, moreover, curved longitudinally so that the ends thereof will flare -away from the conductor to avoid bringing any bending strains thereon such as might occur in the event of swaying or vibration of lthe conductor. This lower clamping member 2 is represented as provided at opposite sides with bosses 4r having vertically extending holes 5 therethrough for the reception of bolt'means to be described. At its center the member 2 is shown as provided with opposed laterally extending trunnions 6 which are preferably integral and which are represented as having downwardly elongated heads 7.

Cooperating with the lower member 2 is an upper clamping member 8 of general elongated form with a transversely curved central seat or channel 9 contacting with the conductor l. The end portions of the member 8 maybe considerably reduced in thicknessr as illustrated at 10, the purpose .being to provide a limited flexibility or yieldabilitv oi the extensions with respect to the body or major portionof the Aupper member 8.

The holding means is here represented as comprising U-bolts 11 which overlie the reduced extensionsY 10 and' which have'their shanks passing through the holes 5 and provided wit-h nuts 12, it being preferable to interpose spring washers 13 between the nuts and the undersides of the bosses 4 to prevent accidental unscrewing of the former.

vThe suspension means is here represented as comprising a pair of links 14 straddling the member 2 andv formed with elongated openings 15 for the passage of thetrunnions 6, the downwardly prolonged heads 7 of these trunnions projecting beyond the lower ends ofthe openings'l so aslto prevent lateral displacement of the links with respect to the clamp when in service. At their upper ends the links maybe apertured at 16for connecticnwith a. Vsuspension element, not shown, at-the lower'end of a string or chain otA lconnected insulators. The axis of the trunnions 6 is preferably at substantially the longitudinalicenter of the conductor, which is the logical yand most advantageous location ofthe pivot. Above the openings 15 the links 14 are provided at their inner faces with fiat ledges or shoulders. 17 which cooperate with pairs ofk lugs 18 which project laterally from the opposite edges of the lupper clamping member 8.

The device is applied to the conductor by placing the clamping members 2 and 8 below and above the conductor and applying the U-bolts T11. lSuspension isv eected by engag-ing the links 14 upon the trunnions 6 and then connecting the links with the insulators from which the conductor is to be suspended. lVhen the nuts 12 are tightened the upper member 8 will lbe drawn down into clamping relation to the member 2 and conductor 1V so that there will be an adequate grip upon theconductorQ Under normal circumstances the ledges or shoulders 17 are spaced slightly below the lugs 18 as clearly indicated in Figure l. c

In the operation, let it be assumed that an unusual strain comes uponthe conductor at one side of the clamp. The rst result will be to swing the insulator string, not shown, sideways, the links 14 ot course swinging out of a vertical position in a corresponding manner. As rocking movement of the links 14 occurs one end of the ledges orv'sho'ulders 17 thereon will engage against one pair 'of lugs 18 and will exert a strong upward thrust thereon tending to move the adjacent extension 10 .of the vupper clamping member upwardly. yAs the extensions 10 are reduced or otherwise vformed to possess iiexibility,'tlie result will be that the intermediate portion of the upper clamping member will be 'leXed upwardly, the other extension 10 fulcruming within the other U-bolt. Clearly this will relieve the clamping pressure of the clamping member 8 upon the conductor 1 so that the latter may slip through the clamp until'the strains at opposite sides of theY clamp have become equalized. VThis action will of course occur all along the line until the excessive strains at anyr points have been'eliminated, thereby permitting the different insulator strings to return to normal position. IVhcn the string in question resumes its normal vertical vposition the links 14 will likewise return to vertical'position, the shoulders 17 then disengaging the lugs 18 and relieving'the strain on the previously flexed member which may then return to normal position exerting its clamping action.

From the foregoing description and a study of the' drawing it will be apparent that I have thus provided a very simply constructed and easily installed clamp which Vwill have the necessary holding action under normal conditions and which will be capable of automatically releasing inthe `event of an unusual strain coming uponV the conductor at one side or the other of the clamp. -Itisbelieved that the construction7 operation and advantages will be readily apparent to one skilled in the art wit-hout further explanation.

While I have shownand described the preferred embodiment of the invention, it should llO be understood that the disclosure is merely an exempliiication of the principles involved spirit of the invention or the scope of 1the claims hereunto appended.

Having thus described the invention, I claim:

l. In combination, a clamping member adapted to support a. conductor, a suspension means for said clamping member, a second clamping member, bolt means connecting said clamping members, and means located above the conductor engaging portion of the second clamping member and cooperating between the suspension means and the second named clamping member for distorting and decreasing the holding action ot the latter.

2. A clamping device of the character described, comprising a pair of clamping members adapted for disposition upon a conductor, bolt means securing said clamping members together, suspension means, and co operating means on the suspension means and one clamping member for distorting` the same and decreasing the holding action of the latter.

3. In a. clamp of the character described,

" the combination of a pair oi clamping members disposable upon a conductor, bolt means securing` said members in clamping relation upon the conductor, suspension means connected with one of said clamping members, and cooperatingmeans on the suspension means and the other of said clamping members for distorting` the latter and decreasing the clamping action thereof.

4. A clamp of the character described comprising lower and upper clamping members, bolt means for securing the clamping members in clamping relation upon a conductor, suspension means pivotally connected with the lower clamping member, and cam means on the suspension means cooperating with the upper clamping member at a point spaced from its center to move the same upwardly at one end thereof with the other end fulcruming within one of the bolt means.

5. A clamp of the character described comprising a lower clamping member having bosses thereon, an upper clamping member having lateral projections at opposite sides of its transverse center, bolts passing through the bosses and each embracing the upper clamping member for maintaining both clamping members in clamped engagement upon a conductor, suspension links pivotally connected with the lower clamping member, and cam elements on the suspension links engageable with one or the other of said lateral projections upon pivotal move-ment of the links with respect to the clamp beyond a predetermined extent for forcing one end portion of the upper clamping member upwardly.

6. A clamping device of the character described comprising a pair of clamping members adapted for disposition upon a conductor, means securing said clamping members together, suspension means, and cooperating means on the suspension means and one clamping member for distorting the same and decreasing the holding action upon swinging movement of the device beyond a predetermined extent.

7. A clamping device of the character described comprising a plurality of clamping members disposable upon a conductor, means securing said clamping members together, suspension means pivotally connected with the assembled clamping members, and means operable upon relative pivotal movement of the suspension means and assembled clamping members for flexing one of the latter and decreasing its holding action.

8. A clamping device of the character described comprising a plurality of clamping members disposable upon a conductor, means securing said clamping members together, suspension means pivotally connected with the assembled clamping members, and means operable upon relative pivotal movement of the suspension means and assembled clamping members for flexing one of the latter and decreasing its holding action, said securing means remaining fixed.

9. A clamping device of the character described comprising an assembly7 of clamping members disposable upon a conductor, means securing said clamping members permanently together, suspension means pivotally supporting` the assembly, and means operable upon relative swinging movement of the suspension means and assembly for flexing and distorting one end of one of the clamping members and thereby reducing the clamping action of the assembly.

In testimony whereof I aliix my signature.

KENT A. HAVVLEY. 

